CSP Steam Turbine

Description

CSP plants require steam turbines which are optimized for their complex and challenging cycle conditions. Bearing in mind that efficiency and total cost of ownership are key to any investment decision, Siemens incorporates its operational experience into extensive R&D and engineering activities to adapt the turbines to the specific requirements of the CSP technology. As market leader in industrial steam turbines, Siemens commands a comprehensive product portfolio for solar thermal plants, covering the full range from 1.5 MW to more than 250 MW.

Design Concept

In order to justify the investment cost for a CSP plant, which will not be run twenty-four hours per day, high demands for efficiency and increasing economic returns are imposed on the steam turbine used in the process. Siemens has cooperated closely with leading solar thermal EPC companies, project developers and operators to develop and fine-tune their steam turbines for solar thermal applications. The highly efficient turbines enable a smaller solar mirror collector field with associated reduction in investment cost for generation of the required electrical power output. Alternatively, the surplus heat can be put into thermal storage to extend the production time for the plant. Day and night cycle often requires a large number of starts and fast daily startup capabilities from CSP steam turbines. When focusing on annual power production, the short start-up times of the turbines are of great benefit to the CSP plant owner. Daily cycling and temperature variations require special attention. Reheat solutions improve efficiency and reduce problems with erosion/corrosion and moisture in the LP turbine. Siemens is able to deliver CSP steam turbines for all power outputs up to more than 250 MW. The turbines meet all customer requirements for economic installation and operation and provide excellent flexibility for all cycling conditions.

Technical Details

Together with EPC contractors and plant developers, Siemens is continuously developing new concepts for steam turbines for CSP applications. Siemens CSP steam turbines have been optimized to handle a wide steam flow range because the solar energy intensity and the cycling conditions can vary according to the weather and time of day. The turbines are suitable for higher steam parameters and can be operated in non-reheat, single reheat and double reheat cycles. Due to their high flexibility and their outstanding efficiency, they fit for all main CSP technologies.

Siemens R&D activities focus on the increase in the internal steam turbine efficiency as well as on cycle efficiency enhancements of the steam turbine configuration e.g., double reheat configuration, supercritical steam parameters. Siemens is continuously reacting on new plant technology trends, e.g., the introduction of simpler solar field designs (e.g., Linear Fresnel) have led to changes in the steam parameters and accordingly to adjustments in the CSP steam turbines.